The long term objective of this research plan is to define the molecular mechanisms which control globin gene expression in humans. Once these mechanisms are defined, more efficient therapies for treatment of the many human hemoglobinopathies may be devised. The specific aims of this proposal are to define the minimal sequences required for high level, adult erythroid-specific expression of the human beta-globin genes in transgenic mice and to isolate the regulatory proteins that interact with these sequences. At least five regions of the beta-globin locus are essential for correctly regulated expression of the beta gene. Three of these regions are located within or immediately surrounding the beta-globin gene itself. The other two regions are located at the extreme ends of the beta-globin locus. The important sequences within all of these regions will be precisely defined by microinjecting globin gene constructs into the nuclei of fertilized mouse eggs and assaying their expression in the animals that develope. Once the minimal sequences required for efficient adult, erythroid-specific expression are defined, proteins that interact with these sequences will be isolated by sequence-specific DNA affinity chromatography. Characterization of these proteins will provide the necessary information for generating oligonucleotide probes or antibodies that can be used to clone the corresponding cDNA's. These proteins and the genes that encode them can then be used to study the basic biochemical mechanisms which control beta-globin gene expression during development.